Printing blanket assemblies or units are fastened on a printing blanket cylinder of a printing press and are used in offset printing for transferring the print image from the forme cylinder to the web of material to be imprinted. To provide the required mechanical strength for the printing blanket unit, a support plate which is made, for example, of sheet steel or sheet aluminum, is employed. A printing blanket, which can be configured in the manner of a rubber blanket, for example, is fastened on the outside of the support plate. Folded or angled plate end legs, which are free of the printing blanket, are provided at the leading end and/or the trailing end of the support plate. These legs are used for fixing the printing blanket unit in place on the printing blanket cylinder. These legs can be inserted, for example, into a slit which is provided in the printing blanket cylinder and can be fixed in place in the slit to secure the blanket assembly to the blanket cylinder.
A problem in connection with known printing blanket units is that the printing blanket does not cover the support plate seamlessly. A gap frequently remains between the leading and the trailing ends of the printing blanket and the support plate. No printing ink can be transferred, in the area of the gap, to the web of material to be imprinted. Furthermore, the print image is of reduced quality at the edges of the printing blanket in the direction toward the gap. Therefore, several solutions are known in the prior art, by the use of which solutions the disadvantages caused by the provision of a gap between the ends of the printing blanket have attempted to be avoided.
A printing blanket unit is known from DE 195 47 917 A1. The two ends of the printing blanket overlap each other with a positive connection in order to reduce the gap that typically is located between the ends of the printing blanket.
A printing blanket unit is known from DE 195 21 645 A1. A slide is arranged between the two legs of the support plate. In this prior art arrangement, the outward pointing end of the slide is connected with a filler element. The gap between the ends of the printing blanket is closed by the filler element.
A printing blanket unit is known from DE 195 43 584 C1. In this device the printing blanket is put together from a plurality of layers. A top layer of the plurality of layers covers the front areas of the layers underneath it and in this way forms a protrusion, by the use of which protrusion the gap at the ends is reduced.
U.S. Pat. No. 5,749,298 discloses a printing blanket unit with a support plate, whose ends are folded. The printing blanket, which is arranged on the support plate, is sealed at the front.
U.S. Pat. No. 4,635,550 discloses a printing blanket unit with a printing blanket arranged on a support plate. A support element is arranged in the groove in the support plate, which support element supports the projecting end of the printing blanket.
U.S. Pat. No. 2,525,003 shows a device for producing a printing blanket unit.
U.S. Pat. No. 4,643,093 discloses a printing plate with a reinforced end and an associated device.